Strategic games, such as chess, checkers, Nim, and Go, have been popular for centuries, and these strategic games continue to be popular forms of creative recreation. Accordingly, it is perhaps not surprising that with the advent of computers, computer-based chess engines have been developed against which a player can match wits. Owing to the extraordinary complexity of strategic games such as chess that stem from the enormous number of move combinations which are possible over the course of the game, chess engines require comparatively fast processors. As processor technology has advanced, so have chess engines.
It happens that chess players who might want to play computer chess range from novice to grandmaster. Stated differently, the consumer of a computer chess product might have a very low chess rating, indicating that the consumer has little or no skill at chess, while another consumer might have a very high chess rating, indicating that the consumer has a great deal of skill at chess. Regardless, the present invention recognizes that it is desirable to provide a computer chess game that is entertaining and challenging for virtually all consumers who might want to match wits against a computer.
Representative of current advanced computer-based chess engines is IBM's "Deep Blue" system. The "Deep Blue" system, like other chess engines such as the WChess engine developed by Heuristic Programming Inc. of Mobile, Ala., has been developed to the point where the equivalent chess ratings of the engine is as high as the ratings of human grandmasters. It readily will be appreciated that current chess engines that can defeat grandmasters will overwhelm ordinary chess players.
To render such advanced chess engines appropriate for use by an ordinary chess player while retaining the ability of the engine to defeat advanced players, systems have been provided that permit a user-player to define the desired skill level, i.e., the rating, of his or her computer opponent, that is, the chess engine. In response to the user's definition, the system disables, i.e., cripples, the chess engine by an amount that will cause the engine to generate moves at the user-defined skill level.
As recognized by the present invention, however, such systems have drawbacks, including the drawback of discouraging a player who wins and believes the victory to be the result of setting the computer's rating too low. Or, a player might set the computer's rating too high, thereby ensuring that the player will rarely if ever win and, thus, dampening the player's enthusiasm for the game. As recognized by the present invention, it would be advantageous for a computer chess brain to automatically adapt to the actual playing skill of a player as evidenced by the player's move, to permit the player to win about 25% of the time. With this win ratio, the player is assured of continuously learning and improving at chess without becoming unduly discouraged at repeated losses.
Accordingly, it is an object of the present invention to provide a strategic game program which automatically adapts to a player's skill level. Another object of the present invention is to provide a computer chess game which is entertaining and educational. Still another object of the present invention is to provide a computer chess game that is easy to use and cost effective.
Other features of the present invention are disclosed or apparent in the section entitled: "BEST MODE FOR CARRYING OUT THE INVENTION."